Automatic switch.



W. L. BLISS.

AUTOMATIC swficu. APPLICATION FILED MAR. 27, 19 11.

Patented Mar. 28,1916.

f Til/671257 M43566 issued Nov. 26, 1997,

Switches,

-the main contacts .open,

WILLIAM L. BLISS, OF IMENTS, TO THE 5'.

NIAGARA FALLS, NEW S. LIGHT &; HEAT CORPORATION, OF NIAGARA. FALLS, NE'illT YORK, ASSIG'NGEL, BY IEESTEE ASSIGBT YORK, A. COBPQBATION OF NEW YORK. f

AUTGMATIC SJVITGH.

To all whom it may concern:

Be it known that I, WILLIAM L.-BL1ss, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of New York, have invented new and useful Improvements in Automatic clear, concise, and exact description, reference being had to the accompanying. drawing, forming a part of this specification.

My invention relates to automatic electric switches.

It is particularly car lighting system, such use.

In car lighting systems a storage battery is employed which is charged by a variable speed generator. When the voltage of the generator exceeds the voltage of the battery an automatic switch closes a circuit between the two, so that the generator may charge the battery. Whenever the generator voltage :talls belowthe battery voltage the automatic switch opens, thereby preventing the battery from discharging through the generator and thus preventing waste of battery current and possible inj'ury to the gen- 'erator. In my prior Patent No. 872,215, I have disclosed an automatic switch for performing the above function. Said switch comprises, in general, a lifting coil connected across the genadapted for use in a although not limited to erator terminals and adapted to close the automatic switch when the generator attains a certain voltage, and a release coll connected in series in the main circuit and adapted to assist the lifting coil in. holding the switch closed. Said release coil also acts differentially with respect to said lifting coil when the battery starts to discharge through the generator, thereby permitting: the automatic switch to fall open. When the main contacts are closed a resistance is automatically inserted in series with the lifting coil to economize current and prevent such heating as might cause said coil to respond to different voltages at diilerent times. ..When said resistance is automatically short circuited. It said short circuiting occurs before suf'licient air-gap has been, established, the sudden increase in the energization of the lifting coil may again close the switch, thereupon automatically inserting said resistance in circuit and Specification of Letters Iatent.

of which the following is a full,

ISatented llfiar. 28, 3.916.

Application filed March 27, 1911. Serial Ho. 617,170.

causing a repetition of operation. In other words, chatter.

My present invention contemplates improvements over prior automatic switches such as Just described, and the object of the invention is to provide means for insuring a positive opening and closing of the main switch contacts, thereby eliminating chattering.

In the accompanyinp, drawings 1 have illustrated a switch which embodies my in vention. The details thereof may, of course, be varied within wide limits without departing from the spirit of the invention.

In the drawings: Figure 1 is a side elevation partly in section, of a preferred form of automatic switch. Fig. 2 is a top view there of. Fig. 3 is a front elevation of the upper portion of th device shown in Fig. 1; Fig. 4 is a diagrammatic representation of the device, showing the circuit connections.

T he automatic switch illustrated coinprises the winding 1 of relatively high resistance, adapted to be connected, for example, in a shunt circuit across the termi nals of a generator, a winding 2 of relatively low resistance, adapted to be connected in series with the external circuit of the generator, a core responsive to the energization of said windings, a resilient contact member 4 carried by said core, and station ary contacts 5. adapted to be bridged by the l the external circuit of the preferably associated with the movable contacts e and adapted to co s'perate with stationary carbon contacts 7 associated with the stationary contacts 5, for the purpose of reducing the arcing when the circuit is opened.

The shunt-connected winding l, which may be called the lifting coil, is energized in response to voltage increase of the generator and is adapted to cause the core 3 to be drawn up and close the main switch, whereby the 'seriesconnected winding; 2 is energized, being; then connected in the external circuit of the generator. T he series winding may be called the holding coil as it assists the lifting coil .1 in holding" the main switch closed after it is energized.

When the core 3 is drawn up, the auxiliary contact 8 issuddenly lifted to introduce resistance 9 into circuit with the lift the above cycle of the switch may ing coil 1. The effectiveness of the lifting coil is thereby diminished and consequently, if for any reason the generator voltage should fall below the battery voltage, battery current will flow through said holding coil 2 in a reverse direction, whereby said holding coil will oppose said weakened lifting coil and the automatic switch will fall open. The resistance 9 also reduces the current flowing through said lifting coil and thereby diminishes th heating effect which might otherwise vary the resistance of said lifting coil to such an extent as to cause the switch to close in response to different voltages at different times.

Theauxiliary contact arm 8 is pivotally mounted and carries preferably an adjustable contact screw 9 adapted to cooperate with a stationary contact 10. In order that the arm 8 may remain in any given position,

suitable springs 11, or other friction devices,

are provided. These springs exert sufficient pressure against the opposite sides of the pivoted-end of said lever to insure the maintenance of said lever in whatever position it may happen to occupy, so that somewhat of a blow is required in order to move said lever either to open or close the auxiliary circuit at the contacts 9 and 10. The various parts of the auxiliary switch are preferably mounted on an insulating member or block 12 secured to the top of the iron frame of the solenoid.

The core 3 is provided with a reduced extension or spindle 13 which passes loosely through an opening in the pivoted arm 8. The core is normally supported by its spindle having suitable nuts 14 thereon, which engage the upper side of the arm 8. The spindle is also provided with a flange or collar 15 adapted to strike said arm 8a hammer-like blow when said core is drawn up for the purpose of overcoming the friction caused by the springs 11 and opening the auxiliary switch. When the core drops, the lower nut 14 strikes the arm 8 a hammer-like blow to quickly close the auxiliary circuit.

The parts are preferably so designed that when theplunger is drawn upwardly, the main contacts engage to close the main circuit before the auxiliary contact is lifted to introduce the resistance into series with the lifting coil. The effectiveness of the lifting coil is therefore not decreased until after the main switch is closed. At this time the air-gap will have diminished sufficiently to prevent the dropping of the plunger, due to the weakening of the lifting coil. When the core drops, the main circuit is opened while the resistance is still in circuit with the lifting coil, said resistance being short-circuited thereafter by the closing of the auxiliary switch arm. By the time the resistance is 'short-circuited, the air-gap is sufficient to prevent a return of the core due to the increased magnetizing effect imparted to the lifting coil. 'By adjusting the nuts 14: or contact 9*, or both, the distance the main contacts move before the auxiliary switch is effective to short circuit the resistance may be readily determined.

It is apparent that I do not desire to limit myself to the various details recited herein but desire to include any suitable equivalent means for accomplishing the desired result and falling within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is

1. An automatic switch provided with an operating coil, a resistance in series with said coil when said switch is closed, and means for short circuiting said resistance when said switch is open, said means being operated by said switch in opening after the switch contacts thereof have separated a predetermined distance.

2. In an automatic switch, switch contacts, means for operating said switch to close said contacts, said operating means also serving to hold said contacts closed, means for reducing the effectiveness of said operating means when said contacts are closed, said last mentioned means also operating to restore the effectiveness of said operating means after said contacts have opened a predetermined distance, and means for varying the distance said contacts may open before said last mentioned means becomes effective.

3. In an automatic switch, a fixed contact, a movable contact, a lifting coil controlling said movable contact, said coil serving to close said contacts and assisting to hold said contacts closed under predetermined circuit conditions, a resistance adapted to be connected in series with said lifting coil, when said coil is serving as a holding coil, to decrease theeffectivenessthereof, an auxiliary switch for bringing said resistance into operation as said main'switch contacts close, and means under control of said switch in opening for causing the effectiveness of said coil to be restored only after said switch contacts have separated a predetermined distance, said last mentioned means being adjustable to vary the distance said contacts may open before said means is operated by said switch.

4. An automatic switch for closing the external circuit of a generator upon predetermined voltage rise, comprising a lifting winding adapted to be connected across the generator terminals to respond to voltage increase, a winding adapted to be connected in series in said external circuit, a resistmain switch in said external circuit adapted to be closed through the energization of said lifting winding, an auxiliary switch normally closed to short-circuit sald resistance whereby full energization of said lifting coil is permitted, said auxiliary switch having means tending to maintain it in any given position, and a loose connection between said main switch and said auxiliary switchfor operating the latter after a predetermined movement of the former has taken place whereby said resistance is connected in circuit with said lifting coil after said main switch has'closed and is not short circuited until after said main switch has opened.

5. In an automatic switch, main switch contacts, an operating coil for controlling the operation of said contacts, said coil serving to close said contacts and also'assisting to hold said contacts closed under predetermined circuitconditions, a resistance adapted to be connected in circuit with said coil to reduce the effectiveness thereof when the'same is acting as a holding coil, means for restoring the effectiveness of said coil, said means being operated by the switch in opening after the switch contacts have separateda predetermined distance, and means for predetermining the distance the main contacts shall separate before the effectiveness of said coil isrestored.

6. In an automatic switch, a fixed. contact, a movable contact, an operating coil for closing said contacts, said coil serving also to assist in holding said contacts closed, a resistance in series with said coil, a short circuiting switch for said resistance, means Operated by said switch in closing for opening :ail short circuiting switch, said means being ineffective to close said short circuiting switch as said main switch opens, and additional means operated by said main switch after the switch contacts have separated a predetermined distance for closing said short circuiting switch, said last mentioned means being adjustable;

7. In an automatic switch, a fixed contact, a movable contact, a lifting coil controlling said movable contact, said coil serving to close said contacts and assisting to hold said contacts closed under predetermined circuit conditions, a resistance adapted to be connected in series with said coil to decrease the efficiency thereof when said coil is serving as a holding coil, an.

auxiliary switch controlling a short circuit around said resistance, said auxiliary switch including a vpivoted contact-carrying lever and means for yieldingly holding said lever in any position to which it may be moved, said lever carrying an adjustable contactto cooperate with a fixed contact, and means under control of said main switch in opening for closing said auxiliary switch to short mined distance, said last mentioned means being adjustable to,vary the distance said I WILLIAM L. BLISS. Witnesses: I

FRED Con, F. A. Scnnmacnnn. 

